


Why You Shouldn't Summon a Demon

by orphan_account



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alternate Universe - Modern Setting, Anal Sex, Demon Summoning, Incubus!Ferdinand, M/M, Oral Sex, Plot What Plot/Porn Without Plot, Rimming, Rough Kissing, bottom!Hubert, ferdinand is also stubborn, hubert is stubborn, no beta we die like Glenn, top!ferdinand, vague modern au
Language: English
Status: Completed
Published: 2020-01-03
Updated: 2020-01-03
Packaged: 2021-02-27 09:54:20
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,666
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22105132
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: When you summon a demon, you usually do it to curse someone, to sell your soul, to offer up a blood sacrifice to gain something in return… at worst, you attempt a ritual of this level to end your own life uniquely.You don't summon a demon to fuck them.
Relationships: Ferdinand von Aegir/Hubert von Vestra
Comments: 11
Kudos: 166





	Why You Shouldn't Summon a Demon

**Author's Note:**

> Everything I write is a horny mess and honestly, I'm just satisfying a need after I realized I got 666 followers in my NSFW on twitter. So uh, here you go, some vague demon fucking I guess.

It wasn't supposed to go like this. When you summon a demon, you usually do it to curse someone, to sell your soul, to offer up a blood sacrifice to gain something in return… at worst, you attempt a ritual of this level to end your own life uniquely. 

You don't summon a demon to _fuck_ them.

One terrible afternoon is what started this. Hubert von Vestra had no need for friends, but because the only person he cared about was the opposite in that regard, he had no choice but to be stuck with people he didn't care for. Usually, he tuned out whatever they were talking about and simply stood by the sidelines, waiting for Edelgard to be done, but the topic of discussion was of his interest for once. 

"I hear that people have been successful with this ritual." Ritual was a word that didn't come out of Dorothea's lips. Hubert subtly turned the page in his book, but his eyes were not reading the words anymore. 

"It's just a waste of time. Why bother summoning a demon? Then you'll have to go along with all their little demands...It's more trouble than it's worth." It was obvious Linhardt would complain about things being troublesome. His iconic yawn even came along. 

"It sounds like you have attempted this already, Linhardt." Edelgard finally spoke, a knowing smile on her face. 

"Of course I have. And it worked spectacularly. I wish it didn't. It's been weeks and I am still suffering the after-effects. Just do yourself a favor and stay out of that business; stick to horror stories." Linhardt said that to no one in particular, but Hubert took it to himself. It was, perhaps, because they made eye contact as he spoke. 

It was no secret that Hubert had an interest in anything 'diabolical'. The man dressed in all black, for heaven's sake, and looked like the most stereotypical goth man to ever step on this earth. But besides that, he too shared a morbid curiosity with Linhardt and he was interested in the topic beyond just wanting to see a demon. 

He already indulged in so much. Magic potions done by his hand getting ingredients that are not so easy to get. Casting hexes on whatever poor victim passed his way when he figured out how to do it right. The man was born to love the ancient arts of Dark Magic, and with each passing year, he only became more and more enamored by it. 

Hubert just had to confirm this conversation with his own two eyes. Seeing is believing, after all. 

This wasn't the first time he had looked into summoning a demon. Truthfully, finding the steps was as easy as typing 'How to summon a demon' on Google. But Linhardt wasn't lying when he said it was more trouble than it's worth. One has to make sure everything is perfect down to the last detail, or it would either go wrong or not work at all. It was best to do it between certain times of the night, and the effects of the ritual may not even be promising. That is to say; you cannot control what demon you end up summoning. 

There are ways to manipulate this, somewhat. Certain objects attract certain types of demons more frequently than others, not to mention the types of summoning circles you draw always have to do with it and let's not forget the material you use to make it. Salt? Ink? Blood? Each of those promised a different result. Flames below, even the type of candles you used was supposed to vary the result. This is not a tried and true type of science, it's more like a lottery with how underdeveloped this area is.

Hubert wonders what kind of ill fate he brought upon himself when he decided to attempt this.

The first time he did so, it didn't work. That day he wasn't feeling well, but a stubborn man like him just couldn't sit idle even in the face of sickness. He must have gotten something wrong, but his pounding head and increasing stomach-ache gave him no energy to try and pinpoint what it was that was missing. He went to sleep with no results.

The second time went a little better. He managed to make the summoning circle become lit, which meant that the Dark energy was filling it with its power. It was promising, but once more, he must have missed something. Maybe the amount of blood he used was not enough, or perhaps he didn't write the glyphs properly… it was rather late and his room dimly lit, he could barely see what he was doing.

By his fifth attempt, he was getting better at this. What was missing was offerings, more Dark energy, things like that. He needed to use a good amount of Dark Magic to make this work, and considering this modern world no longer carried as much magic essence as it used to in the days long past (according to the history books at least), getting the amount he needed took time. He had to be patient. 

His sixth attempt was the one he succeeded. The offerings were delectable and in place. He used ink instead of blood to draw the circle and made sure the glyphs were all written perfectly. Everything was perfect; he made sure it was so.

Why he got such an imperfect result with such preparation was beyond him. 

When he began to see a figure manifesting from the circle, he can't say he didn't become excited. His weeks of work were finally good for something. And well, who wouldn't be excited in a successful attempt at summoning a demon?   
But when the magic dissolved and he was left with a clear view of the being in front of him, he couldn't even appreciate it for more than 2 seconds, for said being instantly let itself come close enough to fall on top of Hubert.

"Finally…" it said above a whisper and Hubert was only able to hear this because the demon was so close. And before he found it in himself to question what in the 9 rings of hell he was doing, his mouth was invaded by one long, thirsty tongue belonging to the demon he had just summoned.

Hubert doesn't have time to thank himself for not setting candles behind him so that when he is pushed to the ground and mounted by this...this thing he didn't accidentally get set on fire. It's hard to shake up the young Vestra, but if one had to pick a way to do this, ' _violating his mouth with your freakishly long tongue_ ' was perhaps the best way to do it. 

It took all of Hubert's strength to remove the beast from him and this didn't come right away. He was distracted by the hands that were now going over his body, making short work of whatever clothes he had put on that night, and the idea that he was being devoured seconds after coming out victorious.

When Hubert managed to push away the demon, his voice came out in a rasp. "What," he gasped out "are you _doing_?" The question was a dumb man but give him a break, there was only so much cool he could keep at this point. 

"Clearly more than you. Why are your hands not on my body?" The nerve of this demon, to order him around like that. He attempted to return to his lips, but Hubert turned his face away from him. "Ugh, seriously? You worked so hard to lure me here and now you will not even take advantage of me?" 

"I beg your fucking _pardon_?" What was he even going on about?! Why would anyone ever summon a demon for that?! 

"Well, why else would you summon an incubus, you overgrown gremlin?" An incubus. Out of all types of demons he could have summoned, he got himself an incubus. 

Hubert is going to be ill. 

"That is not- I did not intend-" Hubert attempted poorly to explain himself, but it was hard to do so when said incubus grew tired of his ramblings and began to suck on the skin of his neck, skillfully getting rid of the shirt the man wore. "I-I cannot control what I summon- _Flames_ , can you stop-" but his protests were unheard, so he had no choice but to forcibly remove the demon again. He earned himself a 'tsk' for that. 

"For hell's sake, have you never gotten laid?! Why would you waste such an opportunity?! I thought human men cared for sex more than anything else! It is why you make such a good prey!" Hubert must be seeing this. He had an incubus in his room and he was whining at him. 

"Opportunity? All I wanted was to summon a demon." 

"Uh-huh, and then what? Invite them for a damn cup of tea? You had to have a plan after you were successful!" 

"I…" and it pained him to admit this, but he had to say it anyway. "I did not think that far ahead." 

"Hell's fire, you are dumber than you look. But whatever; I have already decided that you will do." The demon sat proudly on top of the man and put a hand on his chest, grinning widely at the human beneath him. "My name is Ferdinand. As I already told you, I am an incubus. And today, at your request, I have come to ravage you. Or have you ravage me; whatever it is that you prefer." 

This has to be a sick joke.

"I-" Hubert didn't want to believe this. He didn't want to see this demon, this...very attractive demon. How his golden hair flowed down his chest and down to his hips was sinful. His matching eyes, his proud grin. Hubert's eyes then trailed further down and made him realize that this demon was wearing no clothes. It was foolish to expect an incubus to have anything to cover themselves, considering what it was that they fed off from. The dark marks on his body were more than enough to make him appear to have something on though. And of course, who wouldn't notice the tail that curled around his body, ending in a cliché heart shape. 

All things considered, he was pleasant to the eye, especially Hubert's. But he wasn't about to admit that.

"No answer? Then I will help myself." A grin to reveal his pointed teeth followed these words. "A cutie like you...I wonder what kind of face you make when you come undone." 

It shouldn't come as a surprise when he forces himself onto him again, but it does. Hubert shouldn't be so baffled when the hands come back to hold his body again and bring him closer, but he is. He most definitely shouldn't be impressed at the size of the hardness he feels between his legs, but he is. And just like before, he barely has time to process any of this...this bizarre situation. 

The kiss was sloppy, but he long gave up in trying to stop it. The feelings of fingers tracing over his skin was one that he didn't know he needed and found himself appreciating more. It was hard to resist this demon when said demon worked his charms on him. That had to be what he was doing, or why else would he be getting genuine arousal out of this? This had to be some magic, there had to be some trick behind this that he was simply not meant to comprehend. 

Ferdinand comprehends it all too well, much to his dismay(?). But he also moved on fast. His mouth had been over the other man's a few seconds ago, but now, it was tracing a path over his body. It dragged his tongue along the way, making Hubert squirm under him. He stopped, of course, when he reached over Hubert's hardened cock. A few pumps on the thing and a courtesy lick, but he did not stop there. This isn't where he wanted to land on. 

When Hubert felt an unnatural, cold sensation on his hole; that's where Ferdinand wanted to land on. And Hubert wanted nothing of it. 

“Get yourself off of me-” He weakly protested, but it was caught in his throat and instead he let out a meowl escape it. The face he made upon realizing that he made such an embarrassing sound is one that Ferdinand will not soon forget. 

“Ahaha, you truly are a delight, after all.” The demon practically sang out. 

The position they found themselves in was a bit of a unique one. Ferdinand had moved off Hubert at this point, but he remained seated. So how was he between his legs? Simply put, he decided to bring him to himself, rather than the other way around. His arms wrapped around his waist, he made it so that Hubert’s hole was on the same level as his mouth. His legs went over his shoulders, though he wished that they would do more than hang around uselessly. Wrap them around his head, perhaps? But that was too much to ask out of a bewildered virgin.

“R-Release me…!” Where was all the bite and venom that accompanied Hubert’s words now? It was hard for him to remain cool when he was so compromised. And curse this demon and his very well sculpted arms for being more than just for show and keeping him in place with considerable strength. “ _Curses!_ ”  
  
“Mmm, now now, be a good boy and do not swear. It is most unbecoming of one with such a face.” When he didn’t occupy his mouth, he said stuff that Hubert couldn’t comprehend. But luckily he decided to occupy it again, when he began to lick around, passing his long tongue around parts that Hubert never imagined anyone would.

Hubert squirmed. The cold, wet sensation between his legs was something he recognized as unnatural, something that didn’t belong. Why is it then that he craves more of it? Perhaps it’s his morbid curiosity at its works. After all, he was led to this situation thanks to that. He was a man of science; he just wanted to know more this...this phenomenon. That or the demon’s charms weren’t to be laughed at. 

In time, he might have even grown to accept it. The tongue that had made its home between his cheeks was starting to feel relaxing even. And then it began to probe over his hole, lapping itself over it, and Hubert began to refuse everything he had started to accept.

“No- Stop it-” He called out weakly, looking up to the demon with a defiant glare, or an attempt of one. 

“But how else am I to prepare you? Do you intend for me to go inside you in a raw fashion? Well, aren’t you bold.” His smile wasn’t seen, but it was felt. Hubert hated this man. Or the demon. Whatever the fuck he was.

“You will do n-no such...thing…” Just when he was beginning to get the bile in his tongue to deliver it as Hubert does, Ferdinand’s tongue lapped over his hole again, reminding him of who was in a more vulnerable position. 

“Really? But you seem to be agreeing with it. Your cock is harder than mine, even.” He hated that he had to make his points through actions, because right after he said that, he let his tongue move and extend itself, going so far as to reach his tip that was already leaking out. 

It was then that it occurred to Hubert that he was fully naked in front of someone else. This was something that never happened; it’s something that made him feel utter disgust. And yet, at this moment, he felt as if he had too much on. He still felt like he was being covered, and he wanted to release himself from it. He wanted...to be seen. 

Hubert wanted to be seen. 

“That...you are probably responsible for that.” Hubert countered weakly, but he was not wrong. He was not immune to sexual pleasure, but there was no way he would ever feel comfortable enough in his skin to crave attention. 

“Well, one has to have his charms to get through even the hardest of preys, such as you.” He began to speak after he retreated his tongue, now giving kisses near his hole as if he cared for him genuinely. “But you...you are special to me. There is no way I will let you escape me once again.” Now he must be speaking in riddles, for how the hell would they even know each other? And yet his words seemed to indicate so. 

“What are you going on about this time?” Hubert spat now, indignant. 

Ferdinand giggled. “Nothing. Nothing that you should concern with, at any rate. So then, will you finally stop resisting me? I have the upper hand here. And I know you desire me.” And Hubert knew he was right. So when Ferdinand lapped his tongue over his hole again, he didn’t voice a complaint or let his voice out at all. It was forced out of him though when he later felt the cold muscle shove its way inside. 

“ _Fuck-!_ ” Hubert instantly brought a hand to cover his mouth. No way he would let himself be heard making such pathetic sounds if he could stop it. But Ferdinand’s tongue was skillful and it knew what to do. It knew where to push when to retreat when to go in again. And one of its length was enough to fill his whole. It was...nice. This was starting to feel more than just nice, but Hubert wasn’t ready to admit that.

Ferdinand’s grip on him loosened. In time, he wasn’t even holding him with both hands anymore and instead brought one of his hands to hold onto the poor mortal’s neglected cock and make use of it, stroking the hardened length with skill and ease as his fingers knew exactly how much pressure to add. Pulling his tongue out, he went back to lapping around his hole and what Hubert could only describe as kissing it because he had no idea what he was doing with his mouth as he could not see it, but flames below was it driving him insane. 

Hubert was starting to again get used to this feeling. He was starting to let his guard down and become comfortable. His legs were even wrapped slightly around the demon’s head, just like said demon had wanted him to do so. But the most obvious sign was how much he was leaking and how much he was letting his voice out; a voice that was not meant to be used in this volume. 

The incubus then pulled a fast one, suddenly stopping his actions altogether to look down to his mortal with a sickeningly sweet grin. “Enjoying yourself, darling? You look like you are close to coming and spilling all over yourself.” Hubert couldn’t even reply, he didn’t want to. If he acknowledged his words, that would mean that he lost, and Hubert von Vestra does not lose. 

Hubert was suddenly let go of altogether. He felt his body slide down to the floor, but for like the third time now, he had no time to get into that feeling, for he was brought up suddenly by his wrists. At this point, he felt like a ragdoll being moved around by his master, and he hated to admit it, but he didn’t dislike it. Or any of this. 

What brought him back to his senses was the pressuring feeling of something much harder against his hole. That’s when he realized that he was sitting on Ferdinand’s laps, with Ferdinand’s hands holding him over his cock. “What in the blazes do you think you’re doing?” Hubert was unable to do much more than to ask what was going on, it seems. The poor virgin. 

“Oh please. I gave you so much and you intend to tell me you will give me nothing in return? What I had was barely an appetizer. I do so love to eat your cute little butt, but I will be more satisfy it when I destroy it.” How dare he. How dare he turn him on with such arrogant words. “And you want me as well...I know you do. At the very least, I know you do not want me to leave you here when you have not even come yet.”

“Curses…” Hubert hated how right he was. Again, he was not immune to sexual pleasure, much less when said pleasure was given to him with a pretty face attached to it. So in an act of cooperation, he was the one that guided his own body and aligned it with the cock below him. And soon enough, said cock was buried deep inside as he let himself fall into it, letting out a hiss as he did so.  
  
“There you go...everything is easier when you do not fight it, see?” Despite his cocky words, Ferdinand’s voice was faltering a little more than before. Possibly because he was finally receiving some pleasure to his own body. “Do not worry; my spit is as good as whatever you humans use for lubes. I have to be ready for anything, you see, and this body gives me all the advantages I need for any type of sexual pleasure I decide to indulge in.” 

Hubert wasn’t paying too much attention, but he did notice that it slid in rather easily and that he didn’t feel pain. What he felt was...as if an intruder was inside of him, because it was, but that foreign feeling left him the more time passed and he became more accustomed to it. 

“Well…?” Ferdinand broke the silence when he had finally regained himself. “Are you not- Ah. Of course, you will not.” The cocky grin came back on his lips, his hands suddenly gripping the hips he was holding. “I have to do everything myself. But your face is _so_ cute...I do not mind.”

Hubert’s words were once again caught in his throat when he was suddenly slammed down, and that’s when it began. If he thought what was going on before felt good, then this was a heavenly bliss. Or a cursed one, to be more specific. Who would have thought that being used and filled like this could feel so damn good? He already wanted more of it. 

“So tight…” Ferdinand’s voice slipped out, a comment he mainly made to himself. At some point, Hubert stopped being so reserved and wrapped his arms around the incubus’s neck, holding onto him as if his life depended on it. And the more Ferdinand thrust, the louder he became. He wanted to stop himself; his mind was telling him to, but he couldn’t find the strength to obey it. His thoughts were a mess, it was as if he couldn’t see or hear anything. He could only feel; feel and crave more of that feeling. 

Ferdinand readjusted his angle a little and with a strong thrust, he found himself hitting directly against Hubert’s prostrate and that is when he came undone. Whatever face he was making at the moment must have been horrendously embarrassing because he could hear the demon praise it. Wasn’t this what he wanted to see from the start? Hubert wished he could erase his face, or make Ferdinand unable to see him through any means necessary. But what was he demonstrating with his actions? Quite the opposite. He was begging, pleading for his gaze.

_Look at me._

“So lovely, you are...so very...lovely, my dear…” The incubus chanted as if it was a song. Hubert couldn’t form words, so Ferdinand must have taken it upon himself to do it for them both. Moving his hands to grab what little ass Hubert had, he continued to bury himself deep into him, until soon enough, there was nothing left. "I am so close my love..." He continued to say sweet words like this, but it wasn't like Hubert was paying attention to them. He could barely even tell what was going on at this point. The less the tried to make sense, the better.

Ferdinand leaned forward and bit down on Hubert’s shoulder, hard enough to draw out blood mind you, and gripped on his body as he suddenly released himself into him. And even when Hubert himself reached his end a few seconds later, he could still feel himself get filled up with a sudden sense of warmth and satisfaction. He felt like he was losing himself to this as if he couldn’t do anything more other than pathetically relish on this feeling. 

He felt like a whore. A whore who had reached a blissful point of no return. 

-

At some point, Hubert must have drifted off to sleep. He woke up on his bed and though he didn’t do it right away, upon checking himself, he realized he was fully clothed. He furrowed his brow, naturally confused for his mind carried memories that indicated that he should be anything but clothes, much less his bed. 

“A dream…?” Hubert hardly ever had dreams, and if they ever came to his sleep, they were faceless nightmares. But that was no faceless dream, much less anything close to a nightmare. 

Sitting up, he realized that it couldn’t have been a dream. He felt a soreness he had never felt before, and a sudden dizziness invaded him. Were he standing at the moment, he would have fallen over and crashed on the floor. 

“The floor…” That’s when he turned to look next to his bed, where he had drawn the summoning circle previously. The candles were all consumed at this point, and the offering he had placed was taken, but the summoning circle remained, only that this time, it didn’t look as if it could be erased. It took Hubert a few seconds to realize that it was now carved on the wood of his floor as if it had been there previously.

“Ah, you are finally awake!” 

Hubert immediately reached for the knife he kept under his pillow and pointed it to the direction of the voice, which belonged to the incubus of his dreams, who proved himself to be quite the reality. 

“Wow there, that is no way to thank someone who looked after you!” Ferdinand whined out, looking like a kicked puppy. “I took the time to properly clothe you and put you on the bed, and this is how you return the favor? You are not going to be a very good master, are you?” 

“You...did what?” Was fucking him senseless a part of this ‘good treatment’ of his? And what about now that he is feeling as if someone sucked the life out of him? Whatever little amount he had, anyway?

Hubert is going to be ill. This...this has to be a nightmare, yes. He is still dreaming, surely. This is all just a bad dream. And when he lays down now and closes his eyes to sleep, he will wake up and this ‘Ferdinand’ will disappear from his life, surely. 

“Hey! Are you not going to ask me anything?! Do not just go back to sleep!” But his cries were ignored, which left the demon fuming, but Hubert cared for none of it.

No, he will not ask. How foolish do you think he is, talking to a dream? But the truly foolish one was Hubert, for he was still denying that his life had effectively changed and will never be what it used to be. And when he opens his eyes and is faced with this reality...only then will he realize why you shouldn’t summon a demon.

**Author's Note:**

> yeaaah, me and my best friend ended up building this into a full blown AU as I was writing this, so thats why there's some hints of something more in a few lines that ferdinand says  
> but who knows! maybe ill expand on this, maybe i wont! i probably wont, seeing at this was random as hell LOL
> 
> drop by @R0MBARA sometime will you?


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